03-07-2021, 10:13 AM
Creusois. Before you go to the extreme of machining the cylinder head, I would recommend that you check the clearance available from the valve when fully open. The use of an "extended nose" spark plug rather than a standard electrode could mean the difference between good and bad.
Rather than using an extended nose plug, a standard one should sit flush with the combustion chamber such as shown on post #6 by Nick Lettington. With that in mind you could then machine 3mm off the top surface of the head to accommodate a 19mm plug like the ones in the last photo. Good Luck.
Rather than using an extended nose plug, a standard one should sit flush with the combustion chamber such as shown on post #6 by Nick Lettington. With that in mind you could then machine 3mm off the top surface of the head to accommodate a 19mm plug like the ones in the last photo. Good Luck.